Moiré materials and correlations
In moiré materials, geometry and interactions become tunable on the same energy scale. We study how flat topological bands generate fractional phases, magnetism, superconductivity, and collective modes, and how those states appear in transport, optics, and time-resolved probes.
Local orbitals for topological correlations
Cell Natural Orbitals in Interacting Topological Bands (arXiv, 2026).
Nish, Harshitra, and Dani introduce Cell Natural Orbitals, a local basis that organizes interactions in topological bands through the geometry of their wavefunctions. The construction exposes a hierarchy of interaction channels and connects band topology to real-space correlations.
Correlations in tunable topological bands
A small twist produces a long lattice period and a small Brillouin zone. The resulting bands carry Berry curvature, quantum metric, layer polarization, and valley structure, which determine which local interactions can act and which collective states are possible.
Candidate for a Fractional Topological Insulator in Twisted MoTe2
Physical Review X 16, 031009 (2026).
Polarization-resolved pump-probe spectroscopy separates the magnetic response of fractional fillings from nearby integer states, connecting continuum theory to optical and time-resolved measurements in the same device platform.
Hidden states and dynamics of fractional fillings in twisted MoTe2 bilayers
Nature 641, 1149–1155 (2025).
Ultrafast optical response exposes long-lived hidden states at fractional fillings, resolving dynamics that remain invisible to equilibrium transport and separating correlated phases by their relaxation pathways.
Topologically protected flatness in chiral moiré heterostructures
Physical Review X 15, 021056 (2025).
In the chiral limit, exact band geometry protects flatness across a broad family of multilayer moiré structures. The result turns a special solvable model into a design principle for robust interacting topological bands.
Twist-angle evolution of intervalley-coherent antiferromagnetism in twisted WSe2
Physical Review B 112, 085111 (2025).
Hartree–Fock theory finds a dominant intervalley-coherent antiferromagnetic instability whose stability across twist angle, interaction strength, displacement field, and hole density is controlled primarily by nesting and commensurability. Stronger interactions or smaller twist angles shift the order toward half filling, where commensurability enables a full gap.
Geometric Stiffness in Interlayer Exciton Condensates
Physical Review Letters 132, 236001 (2024).
The superfluid stiffness of an interlayer exciton condensate contains a geometric contribution set by the quantum metric. This connects a measurable collective response directly to the geometry of the underlying moiré bands.
